My J4 has the Dallas Langford PD and AGC mods, as installed by Howard Mills, W3HM, who lives a short drive away.
The Langford mod is similar to Orr’s and Paul Lee’s versions although with different component values here and there. The Langford version is featured in HSN, #28. I’ve been pleased with it. Dan WB4GRA Sent from my iPhone > On Oct 8, 2025, at 3:45 PM, Jacques Fortin <[email protected]> wrote: > > Hi Jim, > Yes, this should have been the Bill Orr PD mod. > As we are there, VE3TOU (Treetops Circuits) made a plug-in PD for it (well, > kind of) see attached. > About trying different tube types on a R-388 PD, I never do it, despite I > have one Collins R-388 but it is still to be restored. > > 73, Jacques, VE2JFE in Montreal > > Jacques > Good catch. > I have a 51J-3 aka R-388 that also had the 6BE6 Product Detector mod > installed. It must have been inspired by the Bill Orr Ham Radio magazine > article. I agree that it doesn't work very well. I removed the mod but > haven't decided on what to do. Either make it work better in SSB or return > it to original condition. I think that there are several pentagrid tubes > that have the same pinout as the 6BE6 but are less noisy with higher gain. > Has anyone tried the 6BY6, 6CS6, 5915 or 7036 in place of the 6BE6? > Jim > Logic: Method used to arrive at the wrong conclusion, with confidence. Murphy > > <R-388_ProductDetector.pdf> > <PD3Manual_Ver8.pdf> > ______________________________________________________________ > R-390 mailing list > Home: http://mailman.qth.net/mailman/listinfo/r-390 > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ R-390 mailing list Home: http://mailman.qth.net/mailman/listinfo/r-390 Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
